The functional plasticity of the nervous system and the brain mechanisms for selective attention are two of the general topics with which this project is concerned. The results o a previous study indcated that evoked potentials (EPs) elicited by both a relevant and irrelevant stimulus, in most brain structures, show similar or unspecific changes during learning. However, the changes in the EPs recorded from the posterior thalamus, in particular the pulvinar, were more specifically related to the meaning and modality of the eliciting stimulus. The present series of experiments will combine behavioral, electrophysiological, histological and pharmacological metods and procedures in order to determine the specific role this region of the brain plays in integrating sensory information during learning. We expect the results of these studies to further our understanding of the underlying causes of "learning disablities" in children.